Regional Blood Flow in the Upper Extremity during and after Exposure to Acute Normobaric Hypoxia

Author： Divert V. E. Komlyagina T. G. Krivoshchekov S. G.

ISSN： 0362-1197

Source： Human Physiology, Vol.30, Iss.6, 2004-11, pp. : 669-673

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Abstract

Cardiovascular indices were analyzed in young healthy males exposed to normobaric hypoxia (breathing a gas mixture containing 10% O₂ for 16 min). There was a marked variation in individual responses. A linear relationship was observed between the individual blood oxygen saturation at the end of exposure and the baseline muscle blood flow (MBF). Moreover, blood oxygen saturation decreased in subjects with an initially high forearm MBF and remained unchanged or even slightly increased in subjects with a low forearm MBF. After hypoxic exposure (10–15 min), the MBF continued to decrease, venous capacity increased, and postocclusion hyperemic response decreased. It is suggested that hypoxic exposure activates the neuroreflex mechanisms regulating the peripheral blood flow and that the peripheral vascular response to acute hypoxia depends largely on the baseline blood flow in skeletal muscles.